General Information

m2 dm 05.03.001

Warning: Keep hands, tools, and other objects away from the scissor points under the seats. Failure to do so could cause personal injury.

Unless otherwise noted, all seat adjustments should be made while seated and before the engine is started.

Due to the high degree of adjustability found in high-back air suspension seats, it is possible to set the seat back recline adjustment and the seat slide adjustment in such a combination that the seat back will come into contact with the rear wall of the cab. It is the responsibility of the driver to adjust the seat to prevent damage to the seat and the cab interior.

The following is a description of adjustments that are available on one or more seats. Not all seats have all of the adjustments listed below.

  1. Seat Slide (fore-and-aft): When this adjustment is made, the entire seat moves forward or backward on its track (see Fig.).

    • Seat Slide (fore-and-aft) Adjustment

    • Isolator Feature

    Fig. 1, Seat Slide Adjustment and Isolator Feature

  2. Isolator: This feature (also referred to as back-slap isolator or Chugger-Snubber®) reduces the amount of road shock by isolating the occupant from the motion of the vehicle, and allowing the upper seat to move in a simple pendulum motion. Whenever the isolator is not desired, it can be locked out (see Fig.).
  3. Lumbar Support: Lumbar support changes the shape of the seat back to give more or less support to the occupant's lumbar (lower back) area. This adjustment is either mechanical or air controlled, depending on make and model of the seat (see Fig.).

    • Lumbar Support

    • Headrest Adjustment

    Fig. 2, Lumbar Support and Headrest Adjustment

  4. Headrest: When this adjustment is made, the upper part of the backrest (back cushion) changes angle to provide head and upper back support (see Fig.).
  5. Backrest Tilt: This adjustment pivots the backrest forward or backward (see Fig.).

    • Backrest Tilt

    • Seat Cushion Tilt

    Fig. 3, Cushion Tilt Adjustments

  6. Seat Cushion Tilt: This adjustment raises or lowers the front and/or back of the seat (bottom) cushion. This adjustment is easier to perform when all weight is removed from the seat (see Fig.).
  7. Seat Tilt: When this adjustment is made, the seat assembly, both backrest and seat cushion, tilts forward or backward (see Fig.).
  8. Ride Height Adjustment: The entire seat moves up or down when adjusting the ride height. The adjustment is either manual or air controlled, depending on the make and model of the seat (see Fig.).

    • Ride Height

    Fig. 4, Ride Height Adjustment

  9. Damper: When you sit on the seat, a leveling valve places you in the center of the ride zone. When the damper is adjusted properly under normal driving conditions, the seat should not top or bottom against the limits of the vertical travel.
  10. Ride Firmness: A firmer ride gives a better feel for the road but less protection against unevenness in the road surface. A softer ride smooths out the bumps.
Note:
Parent topic: Seats
Document Number: 0000117666
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-05-09